A Credit Check?

Hi, I would like to know why a company would need to do a credit check?

I do not have the best credit (husband had open heart with no health insurance)so I do not feel comfortable having these companies looking into my past.

Every time I come up with an item that has a good sell thru rate I find a company and these are the ones that require a credit check. And there are only 2 companies on Salehoo that provide the item I am currently looking at. I will give every tax number reseller number etc. they need but REALLY a credit check?